The removal of sulfur-based species from liquid or gaseous hydrocarbon streams is a problem that has long challenged many industries. Hydrogen sulfide is a huge problem in the oil industry, particularly in the drilling, production, transportation, storage, and processing of crude oil, as well as waste water associated with crude oil. The same problems exist in the natural gas industry.
The presence of sulfur-containing compounds such as hydrogen sulfide can result in the deposition of sulfur containing salts, which can cause plugging and corrosion of transmission pipes, valves, regulators and other process equipment. Even flared natural gas needs to be treated to avoid acid rain generation due to SOx formation. Also, in the manufactured gas industry or coke making industry, coal-gas emissions containing unacceptable levels of hydrogen sulfide are commonly produced from destructive distillation of bituminous coal.
One of the challenges with refining crude oil is that the presence of mercaptans and hydrogen sulfide cannot be dealt with through traditional distillation. In fact, distillation can exacerbate the problem, as mercaptans and hydrogen sulfide tend to contaminate many different distillation cuts, rather than being removed at particular boiling points. Traditional methods of removal from the refinery streams include merox units and hydrotreating. However, merox units are not completely effective and often cause more problems, including caustic contamination of the refinery stream. Additionally, not all refinery streams are hydrotreated and therefore additional methods of dealing with mercaptans and hydrogen sulfide are necessary.
Despite the availability of scavengers for use in the oil and gas industry, there still exists a need for improved compounds, compositions and methods to abate these sulfur compounds throughout the refining process.